The addition of testosterone significantly further improved these measures compared with D&E alone1

All D&E and testosterone treated patients reached the HbA1c glycemic control goal of less than 7.0%, and 87.5% achieved HbA1c of less than 6.5%. In comparison, only 40.4% of the D&E alone participants reached HbA1c less than 7.0%, and none reached less than 6.5%1

Based on Adult Treatment Panel III criteria, 81.3% of the D&E with testosterone patients no longer met the criteria of MetS compared with 31.3% of those receiving D&E alone1

Serum PSA concentrations did not differ between the two treatment groups indicating that 52 weeks of testosterone replacement does not appear to increase risks of prostate problems.1

What is known

Men with T2D have lower serum testosterone concentrations than men without diabetes and there is an inverse association between testosterone levels and HbA1c concentrations.2,3

In men with low plasma testosterone, the risk of T2D appears to be greater4 and a meta-analysis shows that testosterone levels are significantly lower in men with T2D.5

In hypogonadal men, the effect of testosterone supplementation on glycemic control has been mixed. Two studies found no effect,6,7 whereas Kapoor et al (2006)8 found that testosterone replacement therapy improved glycemic control.

Individuals with T2D often have disturbances consistent with the Metabolic Syndrome,9 and individuals with the MetS have increased risk of developing T2D.10

Treatment with exogenous testosterone in those with low testosterone levels has been shown to improve metabolic features of MetS8 and produce beneficial effects on circulating high-sensitive C-reactive protein (hsCRP) levels in individuals with T2D. Some consider low testosterone to be a significant contributor in the development of insulin resistance and MetS in some men.9

Few clinical studies have evaluated the effect of normalization of serum testosterone concentrations on glucose homeostasis6,7 and results from such studies have showed limited beneficial effects of testosterone administration.8

What this study adds

In this study, insulin sensitivity, measured by HOMA, improved in two groups of men receiving supervised D&E. This effect was significantly greater when testosterone was added.1

The changes in both adiponectin and hsCRP were significantly correlated with the therapy induced changes in bio-available testosterone.1These findings are not in line with a previous placebo controlled, randomized study in hypogonadal T2D patients. In these studies, adiponectin levels decreased after 3 to 6 months of treatment with intramuscular mixed testosterone esters.11 (These opposing findings in the circulating adiopnectin concentrations could be a result of the different routes of testosterone administration used with widely variable testosterone levels.)

This study found a decline in serum levels of hsCRP upon D&E plus testosterone, a finding not reported by Kapoor et al (2007)12, but replicated in a study by Haider et al (2009)13.